During embryonic development, the morphogenetic movements of specified groups of cells are carefully orchestrated to give rise to organs with unique shapes and sizes. To understand the mechanism(s) by which such movements occur, we have chosen to study the early development of the embryonic salivary glands of Drosophila melanogaster. Our strategy is to identify mutations affecting salivary gland morphology, and by characterizing the corresponding genes, learn the cellular and molecular basis of cell shape change and cell migration. From a large-scale chemical mutagenesis screen we identified many mutations that cause interesting salivary gland phenotypes, among which is a new allele of hairy which forms branched salivary glands, and a group of mutants which affect the directed migration of the glands. We will determine how mutations in hairy cause salivary glands to branch instead of form uniform tubes, and identify downstream effectors involved in cell shape change. We will characterize the salivary gland migration mutants and identify their corresponding wild-type genes. We will complete the analysis of the remaining mutant lines from the screen and select mutants with possible defects in salivary cell shape change for further characterization. The results of these studies will identify additional genes required for salivary gland morphogenesis and determine how their roles are coordinated to give rise to a tubular organ with a unique shape. The understanding that we gain from these studies will have wide-reaching applications to the formation of other organs as well to certain diseases where cell change shape and tube formation are involved, such as tumor metastasis.